12. Total non-issue.

Every state has DUI laws based on actual impairment regardless of blood level, which cover driving under the influence of everything from alcohol (if the test is unavailable or a person is impaired despite being under the legal limit) to cocaine to cold medicine. Blood level based charges are absolutely unnecessary. For alcohol, they came into vogue because of the ease of testing, the prevalence of alcohol-related incidents, and the ease of making charges stick with an absolute limit versus making a behavior-based case each time.